Deputy Commissioner Susan Frechette said a disturbance can cause adult eagles to abandon their nests, causing the eggs or chicks to die.

She said while bald eagle numbers are increasing in Connecticut, they are still a threatened species in the state. Nesting bald eagles returned to Connecticut in 1993 after an absence of nearly 50 years.

Twenty-three bald eagle pairs were documented in the state in 2011, and 21 of those pairs made nests. Twenty-nine chicks were hatched last year.